Every summer there's this show, one weekend in June, and people from all over the world

come to see it.

It always sells out quickly, but somehow you've managed to get tickets.

And the night of the show, you arrive at a field in rural Pennsylvania.

The guide leads you in a small group out to the venue, this hidden location in the forest

under a canopy of trees that block out the moon and the stars.

As you settle into your seats, night falls, and it's then that the performers finally

show up.

They're in front of you, are hundreds of fireflies.

Not any old ordinary fireflies.

These ones don't blink randomly, but they blink together in unison.

They light up together, then they go dark together.

Light together, dark together, light together.

This is Atlas Obscura, a celebration of the world's strange, incredible, and wondrous

places.

Today, we go to the Pennsylvania Firefly Festival, deep in the Allegheny National Forest.

It's a scientific mystery.

It's a synchronized orchestra of light.

And today we'll hear the story of how the stars of this show almost got burnt out.

That's after this.

Right, so we have five guest bedrooms furnished with antiques.

I made breakfast in the morning.

...